1. Field of the Invention
The invention relates to an ultrasonic sensor device that is capable of transmitting a sensing signal.
2. Description of the Related Art
Shown in FIG. 1 is a conventional ultrasonic sensor device 2, as described in Taiwanese Patent No. M433689. The ultrasonic sensor device 2 includes a housing 21 with a connecting portion 23, and a transducer 24. A circuit board 22 is disposed in the housing 21. As shown in FIG. 2, the transducer 24 has an electrically conductive casing 241 made from aluminum, a piezoelectric member 242 disposed on top of an inner surface of the casing 241, a relaying circuit board 243 disposed above the piezoelectric member 242, and a conductive wire set 244 that electrically interconnects the circuit board 22 and the relaying circuit board 243. The relaying circuit board 243 is further electrically connected to the piezoelectric member 242 via a first connecting wire 246, and to the casing 241 via a second connecting wire 247. The piezoelectric member 242 is operable to generate a sensing signal, which is received by the relaying circuit board 243 and transmitted to the circuit board 22 via the conductive wire set 244. The circuit board 22 is operable to process the sensing signal to generate a processed signal and is mounted with a connecting pin set 221 that includes at least two connecting pins, which serve to output the processed signal and to connect to ground, respectively.
However, such configuration of the conventional ultrasonic sensor device 2 has some drawbacks. For example, connection between the second connecting wire 247 and the casing 241 is typically by soldering, but the casing 241 is made from a material (aluminum) with a very high melting point that makes soldering difficult. Moreover, the conductive wire set 244, the first connecting wire 246, and the second connecting wire 247 are also connected by soldering, thereby making the manufacturing procedure more difficult. Moreover, the conventional ultrasonic sensor device 2 does not have a mechanism to secure the transducer 24, leaving the transducer 24 vulnerable to undesired removal due to external shock. Additionally, the sensing signal generated by the piezoelectric member 242 is relayed the relaying circuit board 243 before being transmitted to the circuit board 22 for processing. It is preferable that the sensing signal be transmitted directly to the circuit board 22 in order to avoid signal attenuation.